George Sperling: Personal Statement

In college, at the University of Michigan, I wanted to be a
scientist, but I didn't know which branch of science, so I majored
in chemistry, physics, mathematics, and biology. Then I did a
brief stint in biophysics before discovering physiological psychology
and, at last, perceptual and cognitive psychology. I received
my Ph.D. from Harvard in 1959 for a thesis on short-term memory.
My goal then, as now, was to apply the quantitative and theoretical
methods of the hard sciences to the analysis of cognitive processes.

My early research dealt with empirical studies of human information
processing (very short-term visual memory systems, post-stimulus
masking, and the like) and with mathematical/neural models of
the visual processes of light adaptation, flicker sensitivity,
contrast detection, and stereopsis. More recently, Adam Reeves
and I developed a mathematical theory for temporal attentional
filtering, and a corresponding psychophysical method for measuring
shifts of visual attention. Erich Weichselgartner and I exploited
these methods to show that movements of attention across the visual
field are quantal not analog, and to measure the different dynamics
of automatic and controlled attention. We also developed a general
method for measuring the time course of almost any perceptual
event, and applied it to the perception of extremely brief flashes.
Shui-I Shih and I developed a paradigm to show that early attentional
filtering in search tasks, which is possible for space or time,
works indirectly for physical features such as "colors",
by enhancing processing at the locations and times at which attended
colors occur. Steve Wurst, Zhong-Lin Lu, and I studied how
attentional filtering in many feature dimensions and in combinations
of dimensions can control the input to short-term memory. Revisiting
an early theme, Karl Gegenfurtner and I worked out a computational
model for the acquisition and decay of items in iconic memory.

Jan van Santen and I developed a mathematical theory based
on elaborated Reichardt detectors to account for many of the essential
phenomena of classical motion psychophysics. Then, Charles Chubb
and I discovered motion displays that would be invisible to all
motion detector mechanisms that had thus far been proposed, including
Reichardt detectors. With these displays, we identified second-order
motion and pattern perception systems not known previously, work
that continued with Joshua Solomon and Peter Werkhoven. Recently,
Zhong-Lin Lu and I developed a "pedestal" paradigm that
enabled us to isolate and characterize the three visual motion-perception
systems that operate simultaneously in human perception. Other
projects, with many collaborators, involved dynamic image processing
of American Sign Language to enable it to be transmitted on ordinary
telephone channels. In teaching, I noted that precisely the same
optimization computation is used in signal detection theory and
in resource theories of attention. Barbara Dosher and I found
that a similar optimization theory applies to cognitive strategies
in information-processing tasks.

Some of the projects listed above have yielded such detailed
flowcharts of "cognitive microprocesses" that it seemed
it might be possible to localize these processes in the brain.
So, recently, I've begun work in brain imaging with fMRI, and MEG,
mainly in collaberation with Zhong-Lin Lu, as well as EEG (SSVEP)
with Ramesh Srinivasan. The focus has been the
identification of brain mechanisms of motion perception and attention.

I discovered early that collaborative research is the most
fun, and my current research continues the themes in vision
and attention with student, postdoctoral, and faculty colleagues.

The Human Information Processing Laboratory, where these projects
are carried out, offers computer facilities for almost any project
in perception or cognition. Students learn about cognitive science
and also acquire facility with computer systems, with complex,
modern experimental techniques, and with methods of modeling and
formal theory construction, and develop the diverse technical skills
they need to work at the forefront of knowledge. (2010)

Sperling, G. (1988). The magical number seven: Information processing
then and now. In W. Hirst (Ed.), The making of cognitive science:
Essays in honor of George A. Miller. Cambridge, UK: Cambridge
University Press. Pp. 71-80.

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